Re-Installing My Supercharger

[iniazy]

I've decided to replace the bypass valve with a blow-off valve. I know my Kuwaiti friend, with the URD kit, managed to gain a couple PSIs by cancelling the bypass valve and relying completely on the blow-off valve. It is very likely the cause of the problem.

I tested it by blowing into the valve while the car is off, and I couldn't blow through it. But probably with proper pressure it is able to blow through it during boost.

My Rotrex sure has been through serious abuse when it was on the Alpine mounting kit. The tensioner wasn't dynamic, the crank pulley wasn't perfectly centered, and the belt would occasionally jump out of the crank pulley guides resulting in tremendous tension on the two pulleys, which is probably what broke my timing chain cover twice. But since I put on this Bullet Cars mounting kit, the supercharger has been trouble-free, a perfectly designed system, kudos to them for doing such a good job. The loss of boost only happened very recently.

 

[iniazy]

And an update. It's been a while since I last posted, been working on getting replacement parts, trying different stuff, and so on, to get to the bottom of the boost loss.

I ordered a QR-type TiAL blow-off valve, used the -16 to -19 psi spring, welded the weld-on flange, and took the car for a spin. Still, only reaching 9.4 psi, no more. So I decided to put a smaller pulley, 75 mm, and that seems to have cured the problem. At least now I know there is no boost leak, I'm thinking maybe the Rotrex unit lost some efficiency.

So upgrading the pulley from 80 mm to 75 mm has raised the boost from 9.4 to 11.2! That seems like a huge increase for only one step pulley upgrade! Considering my 80 mm pulley was a two-step upgrade and originally increased boost from 8.6 to 10.7 before the boost loss happened. The engine doesn't seem to be so happy with that level of boost, and the heat levels we're having in Saudi Arabia, it knocks at top RPM WOT. So I better take it easy while waiting for Fall to come and weather to cool off.

Anyway I'm happy I replaced that no brand bypass valve with a TiAL, which is customizable and top notch quality.

Now for some pictures:

The old BOV cut off with an angle grinder:



Charge pipe with the hole in it:


TiAL QR BOV:






Mock-fitting:


Flange welded:


And painted:


And BOV fitted:


While I was at it I installed a small Flex-a-lite fan on my intercooler heat exchanger to shed off some more heat:


It fits just right between the two heat exchangers:

 

[iniazy]

I believe it is time to think about a water/meth injection installation. At the midst of the heat season here it is just too hot for boost, I have to do something about it.

I bought a weld-on bung for the nozzle:


I haven't welded it on yet, just preparing to do it in the near future. I think it is absolutely necessary for this level of boost in the midst of the Saudi heat.

 

[Torspd]

That looks so much more professional with the QR on there. I know it will perform better, for certain. :top:

What are your ambient temperatures and what does your coolant temperature normally run in the heat of the day?

 

[iniazy]

We are running into 48 degrees C (118.4 F) but last night it was around 38 C (100.4 F), I forgot to check my coolant temp, but it was normal, I would think around 90 degrees C (194 F), especially that the weather was extremely humid, and humidity helps cool things down.

It runs fine first couple of runs, then starts knocking. It's the water-air heat soak problem.

I'm really surprised and pleased my engine is taking all that abuse. So many times I hear violent knock over the course of the 1.5 years I've been tuning the car, and so many times I think "Oh no, I hope I didn't crack a piston!"

 

[HAMHAWK_JAY]

I want to see where this goes i'm interested now

 

[Torspd]

Surprised and thankful for you as well. With what you say about the knocking. I have cracked many a piston. Lol.

I am also curious what your IAT's are, at those temperatures. Inlet Air Temps.

Currently with the heat here, my engine runs around 194 to 204 F. IAT's have been 103 even while cruising.

 

[iniazy]

Mine gets up to 65 - 70 (149 - 158 F) degrees while idling, and 45-55 (113-131 F) while driving. I used to feel bad about it, but now I feel all the better. Wow, 200 F for IAT is a LOT! And you don't even reach our levels of heat. Must be the Turbo thing. Turbos make lots of heat.

I've also just done something that might reduce IAT a bit, I cancelled the recirculation of the BOV. I thought this might be causing the SC intake to pull in more heat, and heat may be building up as I go. Because my BOV is not after the intercooler, it recirculates hot air blowing straight out of the SC, when at vacuum. I'm not sure this will have a negative affect, but I did it just in case. I don't need recirculation because I've cancelled MAF and now use MAP.

 

[justin13703]

Mine gets up to 65 - 70 (149 - 158 F) degrees while idling, and 45-55 (113-131 F) while driving. I used to feel bad about it, but now I feel all the better. Wow, 200 F for IAT is a LOT! And you don't even reach our levels of heat. Must be the Turbo thing. Turbos make lots of heat.

I've also just done something that might reduce IAT a bit, I cancelled the recirculation of the BOV. I thought this might be causing the SC intake to pull in more heat, and heat may be building up as I go. Because my BOV is not after the intercooler, it recirculates hot air blowing straight out of the SC, when at vacuum. I'm not sure this will have a negative affect, but I did it just in case. I don't need recirculation because I've cancelled MAF and now use MAP.

Pretty sure that he was saying that his coolant temps run around 200 degrees, not his IAT. He was saying that his IAT was 103 while moving.

As far as your supercharger recirculating heated air, yes there may be a small temp rise when the air is recirculating. But I am willing to bet it's so small it won't cause any negative affects. What creates the heat is the compressing of the air when the sc is creating boost. While it is recirculating, there is no compression therefore no heat. And being that it is a supercharger instead of a turbo, you are also not picking up heat from the exhaust manifold. Your supercharger, when it is recirculating air, is basically a fan. Not generating much heat. Just moving air.

 

[Torspd]

Pretty sure that he was saying that his coolant temps run around 200 degrees, not his IAT. He was saying that his IAT was 103 while moving.

As far as your supercharger recirculating heated air, yes there may be a small temp rise when the air is recirculating. But I am willing to bet it's so small it won't cause any negative affects. What creates the heat is the compressing of the air when the sc is creating boost. While it is recirculating, there is no compression therefore no heat. And being that it is a supercharger instead of a turbo, you are also not picking up heat from the exhaust manifold. Your supercharger, when it is recirculating air, is basically a fan. Not generating much heat. Just moving air.

Correct. 103 IAT's while cruising.

 

[iniazy]

Pretty sure that he was saying that his coolant temps run around 200 degrees, not his IAT. He was saying that his IAT was 103 while moving.

As far as your supercharger recirculating heated air, yes there may be a small temp rise when the air is recirculating. But I am willing to bet it's so small it won't cause any negative affects. What creates the heat is the compressing of the air when the sc is creating boost. While it is recirculating, there is no compression therefore no heat. And being that it is a supercharger instead of a turbo, you are also not picking up heat from the exhaust manifold. Your supercharger, when it is recirculating air, is basically a fan. Not generating much heat. Just moving air.

I figured the same, just decided to do it just in case. Though your argument makes perfect sense.

 

[Torspd]

That new Catapillar phone with the thermal imaging FLIR camera, would be great to test that theory.

 

[iniazy]

I've been researching my auto transmission issue, I'm facing a problem when accelerating full throttle, when the transmission upshifts during hard acceleration it suddenly gets excessively rich, up to 9:1 and some times touches the 8.8-8.9:1, which is REALLY hurting my acceleration.

I found that my A750F transmission has an electronic system called "Engine Torque Control", the transmission sends a signal (I think) to the engine to retard the timing during upshifts to make the shifts smoother. With the much larger injectors in, this activity results in excessive richness during that period. This is how the transmission documentations describe this system: "Retards the engine ignition timing temporarily to improve shift feeling while up-shifts or downshifts occur."

I'm trying to figure out how this signal is sent to the ECU, so I can intercept it and stop it, or at least reduce it. Haven't found out yet.

I'm looking into aftermarket transmission controllers too, to see how difficult it is to install them and use them. If I get the transmission controlled outside the Engine ECU, then I can easily install a stand-alone engine control unit like Haltech Elite.

Other than that, my engine is performing really nicely, I'm really happy with the new power levels, and I managed to control that knock at WOT.

That new Catapillar phone with the thermal imaging FLIR camera, would be great to test that theory.

I am not sure I understand what you are talking about.

Edit: Here's what I've found so far:


So those are the scenarios where ECU adjusts ignition timing. The one I'm concerned with is the "Torque Control Correction" signal, anothe rname for "Engine Torque Control". It drops timing to about 20 degrees.

It uses the following to decide on how much or whether it should retard timing:
1. Throttle position
2. Engine speed
3. Coolant temperature
4. Vehicle Speed

Apparently it will not retard when coolant is below a specific level, but I still don't know what is that level.

So here's what I need to do, cut this signal:


Now my quest is to find which wire transmit this signal. Or maybe clamp the coolant temp. voltage to make the ECU think it did not reach the necessary temp. to perform the timing retard. That may have other ill-affects, so I probably will not resort to that.

 

[Torspd]

It is in reference to how hot the air is which gets recirculated. That phone which I mentioned, has an internal thermal imagining camera.

Speaking of Haltech, I have my eyes on the Elite 2500. With a plug n play harness from Boomslang.

It will be as simple as setting up the throttle control for the MAP-ECU3, except it has full control. Therefore disabling the throttle body speed governor. It is such a pain on the ProEFI.

 

[iniazy]

It is in reference to how hot the air is which gets recirculated. That phone which I mentioned, has an internal thermal imagining camera.

Speaking of Haltech, I have my eyes on the Elite 2500. With a plug n play harness from Boomslang.

It will be as simple as setting up the throttle control for the MAP-ECU3, except it has full control. Therefore disabling the throttle body speed governor. It is such a pain on the ProEFI.

Wow that's awesome! I didn't know there was a plug-n-play harness for the 1GR and Elite 2500! I just looked at Boomslang site, and found it there.

I am seriously considering going for a stand-alone Transmission Control Unit, and if I do, then the door is open to get a Haltech Elite 2500 altogether.

 

[TRON]

Haltech elite 2500 + boomslang harness :top:

 

[Torspd]

I was just speaking with my friend yesterday, and he was telling me about the new Aem Infiniti 7. Said that it can control the transmission. Being that he has a 4Runner, and doesn't want a stand alone controller for the transmission, he has decided this route.

Just another option to consider. :top:

 

[iniazy]

I was just speaking with my friend yesterday, and he was telling me about the new Aem Infiniti 7. Said that it can control the transmission. Being that he has a 4Runner, and doesn't want a stand alone controller for the transmission, he has decided this route.

Just another option to consider. :top:

That's interesting. I'll research it.

 

[iniazy]

OK now something really must be wrong with my supercharger.

With the 80 mm pulley first installed I got 10.7 psi of boost. After a while it went down to 9.3.

I tried several things to try to find the source of boost loss, nothing seemed to be wrong. So I upgraded the pulley to 75 mm. That brought the boost back up to 11.2.

Now even with the 75 mm pulley I'm barely hitting 9 psi.

No vacuum leaks at all anywhere.

Has anyone had supercharger efficiency problems before? Why is my supercharger losing efficiency

 

[Gadget]

I really have not heard of a problem like that with the supercharger. If they start to slip internally they self destruct pretty fast.

I would suspect you have a problem in your belt drive after you rule out a clogged air filter.

G